The publication is meant to be a bridge between the scientific community who investigates drug addiction and those who make drug addiction policies and develop drug addiction programs. Articles are included on the social and legislative perspectives of drug use in Mexico, linguistic analysis of drug slang, recent tendencies toward cocaine use in Mexico, and genetic and/or social transmission of drug addiction. Reports are presented on research into drug maintenance using morphine, on intravenous drug use and AIDS in Mexico, and on the psychiatric consequences of drug and alcohol consumption. The biological and lung damage effects of tobacco are reviewed in two studies, and the validation testing of a national drug evaluation scale is reported.